ROSEMONT, CA - A teenage girl who was found dead in a Rosemont park six months ago was alone when she walked to the park on March 5, according to new surveillance video that was released by the Sacramento County Sheriff's Department Thursday.

The 30-second video shows Jessica Funk-Haslam, 13, walk around a corner in a neighborhood, near the Rosemont Community Park, around 6:30 p.m. on Monday, March 5.

Funk-Haslam was found dead on Tuesday, March 6 around 6:30 a.m. by a passerby in the dugout of a baseball diamond at the park. The Sacramento County Coroner's Office report said the cause of death was blunt force trauma to the head, a stab wound and asphyxiation.

The 13-year-old was last seen by her family around 5:30 p.m. Her father Allen Porter said, in a March 6 interview, he talked to Funk-Haslam on the phone around 6 p.m. Porter said Funk-Haslam got into an argument with her mother the night of March 5.

Investigators have been trying to figure out Funk-Haslam's whereabouts between when she was last seen by her family and her time of death, estimated to be between 8 p.m. and 10 p.m. on March 5, said sheriff's detective Tony Turnbull in March 15 interview.

Investigators learned that Funk-Haslam took a light-rail and a bus to get to the park. The video shows her walking towards the park at 6:30 p.m. Turnbull said a neighbor near the park reported hearing screams between 8 p.m. and 9 p.m.

Surveillance video from a home near the park showed a person running near the intersection of Rosemont Drive and Contempo Drive, which is near the park, during the same time frame investigators believe Funk-Haslam was murdered. Turnbull said the person was not a suspect, but detectives wanted to talk with him or her to figure out any information about the crime.

Detectives also recovered surveillance video from Albert Einstein Middle School in March. According to Turnbull, five men, who appear to be teenagers to early adults, were seen on the video entering the park between 6:30 p.m. and 9 p.m. Detectives are trying to identify the men, who they believe may have seen Funk-Haslam at the park.

"I want to reiterate as I have done several times that this is by no means is a cold case; despite the fact that no new information has come forward." Deputy Jason Ramos said. "We have detectives that continue to work aggressively on this."

A vigil is scheduled to be held on Sept. 7 at 5 p.m. to remember the 6-month mark since Funk-Haslam's murder. Organizers plan to tie pink ribbons with zebra print ends to trees to honor the teen and remind people that the case is not solved.

"It's unsettling," parent Jennifer Nidoy said. "I used to let my son come here by himself and he's a football player, and I tell him no you can't go there alone."